diff --git a/BuildingSync.xsd b/BuildingSync.xsd
index ba6b5147..5d42f1b2 100644
--- a/BuildingSync.xsd
+++ b/BuildingSync.xsd
@@ -6863,8 +6863,16 @@
                             <xs:attribute name="IDref" type="xs:IDREF" use="required"/>
                           </xs:complexType>
                         </xs:element>
-                        <xs:element ref="auc:Capacity" minOccurs="0"/>
-                        <xs:element ref="auc:CapacityUnits" minOccurs="0"/>
+                        <xs:element ref="auc:Capacity" minOccurs="0">
+                          <xs:annotation>
+                            <xs:documentation>WARNING: This element is being deprecated, use auc:Capacity of linked systems instead.</xs:documentation>
+                          </xs:annotation>
+                        </xs:element>
+                        <xs:element ref="auc:CapacityUnits" minOccurs="0">
+                          <xs:annotation>
+                            <xs:documentation>WARNING: This element is being deprecated, use auc:CapacityUnits of linked systems instead.</xs:documentation>
+                          </xs:annotation>
+                        </xs:element>
                         <xs:element ref="auc:PrimaryFuel" minOccurs="0">
                           <xs:annotation>
                             <xs:documentation>Main fuel used by the system.</xs:documentation>